Writing instrument



FIG. 1 is a front elevational view of a writing instrument in accordance with my design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a bottom plan view thereof; and,

FIG. 5 is a top plan view thereof. 

CLAIM The ornamental design for a writing instrument, as shown and described. 